Epidemiology is a traditional subject mainly based on principles and concepts, and its teaching method needs further improving to meet the requirement of the new trend of education reform. Lecture-based teaching, problem-based teaching, case-based teaching, and internet based teaching, such as flip class, massive open online course and micro-lecture, all have its own unique merits in the practice of epidemiology teaching. So the combination of traditional teaching and online teaching is the most promising mode. "Rain class" , a mixed mode, is an efficient tool to present the epidemiology case more actually in class. Thus, teaching design and application of "rain class" are worth research.
Computer-Assisted Instruction ; Epidemiology/education* ; Humans ; Internet ; Online Systems ; Research ; Teaching

Objective: To investigate the effects of hepatitis B virus (HBV) genotype and mutations on the development of hepatocellular carcinoma (HCC) and to establish a new qualified HCC risk scores. Methods: A cohort study enrolling patients with chronic HBV infection was conducted. HBV genotypes were identified by nested multiplex PCR. HBV mutations in the basic core promoter region and PreS region were sequenced after PCR amplification. Scores on risk factors were set based on nomogram. Results: Totally, 1 525 patients were followed-up in this research. A total of 1 110 patients infected with genotype C were followed-up for 8.52 (Q(R): 5.36-11.68) years on average, of whom the incidence of HCC was 11.93/1 000 person-years. In genotype C HBV infected patients, male gender, aged 40 years and over, and four DNA mutations (T1674CG, A1762T/G1764A, A3120T, and A2962G) can increase the risk of HCC (P<0.05); interferon therapy can reduce the risk of HCC (P<0.05). A new HCC predicting model was established according to the results. After validation, the predicted disease-free survival rate was consistent with the real one. Conclusions: Hepatitis B virus genotypes and mutations were closely associated with HCC. The new risk scoring system can well predict HCC occurrence in genotype C HBV infected patients.
Adult ; Aged ; Carcinoma, Hepatocellular/virology* ; China/epidemiology* ; Cohort Studies ; DNA, Viral/genetics* ; Female ; Genotype ; Hepatitis B virus/genetics* ; Hepatitis B, Chronic/complications* ; Humans ; Liver Neoplasms/virology* ; Male ; Middle Aged ; Mutation ; Predictive Value of Tests ; Risk Factors ; Sensitivity and Specificity

OBJECTIVE This study aimed to determine the relationship between individual allergens with current wheezing and bronchial hyperresponsiveness (BHR) in schoolchildren from three chinese cities: Beijing, Guangzhou and Hong Kong. METHODS Community-based random samples of 10-yr-old schoolchildren from the 3 cities were recruited for study using the International Study of Asthma and Allergies in Childhood (ISAAC) Phase II protocol. The subjects were studied by parental questionnaires (n = 10,902), skin-prick tests (n = 3478), and methacholine challenge tests (n = 608). RESULTS The highest prevalence rates of wheezing in the past 12 months (Beijing, 3.8%; Guangzhou, 3.4%; Hong Kong, 5.8%) and atopy (Beijing, 23.9%; Guangzhou, 30.8%; Hong Kong, 41.2%, defined as having Allergens ; classification ; immunology ; Asthma ; etiology ; immunology ; Bronchial Hyperreactivity ; etiology ; immunology ; Child ; China ; Hong Kong ; Humans ; Risk Factors ; Skin Tests ; Surveys and Questionnaires

Objective: To investigate the infection pattern and etiological characteristics of a case of human infection with highly pathogenic avian influenza A (H7N9) virus and provide evidence for the prevention and control of human infection with highly pathogenic avian influenza virus. Methods: Epidemiological investigation was conducted to explore the case's exposure history, infection route and disease progression. Samples collected from the patient, environments and poultry were tested by using real time reverse transcriptase-polymerase chain reaction (RT-PCR). Virus isolation, genome sequencing and phylogenetic analysis were conducted for positive samples. Results: The case had no live poultry contact history, but had a history of pulled chicken processing without taking protection measure in an unventilated kitchen before the onset. Samples collected from the patient's lower respiratory tract, the remaining frozen chicken meat and the live poultry market were all influenza A (H7N9) virus positive. The isolated viruses from these positive samples were highly homogenous. An insertion which lead to the addition of multiple basic amino acid residues (PEVPKRKRTAR/GL) was found at the HA cleavage site, suggesting that this virus might be highly pathogenic. Conclusions: Live poultry processing without protection measure is an important infection mode of "poultry to human" transmission of avian influenza viruses. Due to the limitation of protection measures in live poultry markets in Guangzhou, it is necessary to promote the standardized large scale poultry farming, the complete restriction of live poultry sales and centralized poultry slaughtering as well as ice fresh sale.
Animals ; Chickens ; China ; Commerce ; Humans ; Influenza A Virus, H7N9 Subtype/pathogenicity* ; Influenza in Birds/virology* ; Influenza, Human/virology* ; Phylogeny ; Poultry/virology* ; Real-Time Polymerase Chain Reaction ; Zoonoses

Objective: To understand the situation related to health seeking and diagnosis of imported malaria and to provide practical measures for malaria elimination in Jiangsu province. Methods: Data on imported malaria cases in Jiangsu province was retrieved in CISDCP from 2014 to 2016. Relevant information on health seeking behavior, diagnosis and treatment of the disease was gathered. Results: A total of 1 068 imported cases were reported in Jiangsu province from 2014 to 2016. Except for one malaria case that was caused by blood transfusion, the rest patients were all recognized as 'imported'. Majority of the cases were migrant laborers working in African countries. The accurate rates on the diagnosis of ovale, vivax and quartan malaria and mixed infection were relatively low, as 79.3% (107/135), 29.5% (18/61), 52.9% (18/34) and 0.0% (0/2) at the primary health care settings, respectively. Rate of seeking health care on the same day of onset was more in 2015 than in 2014 and 2016 (χ(2)=18.6, P=0.001). While only 65.4% (699/1 068) of the patients were diagnosed correctly at the primary health care settings. There appeared no statistical difference in the 3-year-study period (χ(2)=5.4, P=0.246). Capacity on 'correct diagnosis' seemed stronger at the CDC than at the hospital levels (χ(2)=13.2, P=0.000; χ(2)=5.4, P=0.020). Totally, 72.7% (32/44) of the severe falciparum malaria cases did not immediately seek for health care when the symptoms started. Conclusions: Migrant workers returning from the high endemic malaria areas seemed to have poor awareness in seeking health care services. Capability on correct diagnosis for malaria at the primary health care settings remained unsatisfactory and staff from these settings needs to receive adequate training.
Adult ; China/epidemiology* ; Female ; Human Migration ; Humans ; Malaria/transmission* ; Male ; Middle Aged ; Plasmodium/isolation & purification* ; Prevalence ; Seasons ; Transients and Migrants ; Travel

Objective: To carry out a quantitative estimate that related to the effects of short-term exposure to PM(2.5) on all-cause mortality and emergency visits in China by using the systematic review and Meta-analysis. Methods: We selected all the studies published before March 2018 from China National Knowledge Infrastructure, Wanfang database, PubMed and EMBASE and data on relative risk (RR), excess risk (ER) and their 95%CIs: appeared in these papers were extracted. According to the differences in the size or direction (heterogeneity) of the results, we computed summary estimates of the effect values using a random-effect or fixed effect model. We also conducted the subgroup analysis and Meta-analysis to have assessed the selected studies for the evidence of study bias. Results: A total of 33 original studies, indexed in databases, were identified. Among those studies, 39 sets of data on mortality and 4 sets of data on emergency were valid to show that within the daily concentration range from 47.7 to 176.7 μg/m(3), for 10 μg/m(3) increases in PM(2.5) concentrations, it would increase the daily numbers of deaths by 0.49% (95%CI: 0.39%-0.59%) and 0.30% (95%CI: 0.10%-0.51%) for all-cause deaths and all-cause emergency-room visits, respectively. For subgroup analysis, the combined effect of PM(2.5) in causing short-term all-cause deaths in the northern areas (ER=0.42%, 95%CI: 0.30%-0.54%) seemed lower than that in the southern areas (ER=0.63%, 95%CI: 0.44%-0.82%). The combined effect of PM(2.5) concentration below 75 μg/m(3) (ER=0.50%, 95%CI: 0.37%-0.62%) was higher than that of PM(2.5) concentration ≥75 μg/m(3) (ER=0.39%, 95%CI: 0.26%-0.52%). Conclusion: Within the concentration range from 47.7 to 176.7 μg/m(3), short-term exposure to current level of PM(2.5) might increase both the all-cause daily mortality and daily emergency visits in China.
Air Pollutants ; Air Pollution/statistics & numerical data* ; China ; Databases, Factual ; Emergency Service, Hospital/statistics & numerical data* ; Environmental Exposure/statistics & numerical data* ; Female ; Humans ; Male ; Particulate Matter/toxicity* ; Time Factors

Objective: To explore the reasons and factors associated with new psychoactive substances abuse among patients with access to methadone maintenance treatment (MMT). Methods: A well-developed questionnaire and urine tests were used to collect information about demographic characteristics, condition of MMT and drug abuse, family and social support of MMT clients. A 1∶1 matched case-control study was conducted, and conditional logistic regression model was used to identify factors associated with new psychoactive substances abuse. Results: A total of 212 (106 pairs) clients receiving MMT were recruited, and most of them were males (78.3%, 166/212), married or cohabitant (48.6%, 103/212) and unemployed (63.2%, 134/212). The average age of the clients was (45.1±7.2) years. The main types of abused new psychoactive substances were benzodiazepine (62.3%, 66/106) and methamphetamine (39.6%, 42/106). The proportion of abusing multi new psychoactive substances was 8.5% (9/106). Results from multivariate conditional logistic regression analysis indicated that using opioid drug during the past 6 months of MMT treatment might increase the risk of abusing new psychoactive substances (OR=3.25, 95%CI: 1.35-7.79), benzodiazepine (OR=3.25, 95%CI: 1.11- 9.47) and methamphetamine (OR=13.31, 95%CI: 1.12-158.01). Moreover, MMT for more than9 years reduced the risk of abuse of new psychoactive substances (OR=0.03, 95%CI: 0.01-0.21), benzodiazepine (OR=0.02, 95%CI: 0.00-0.36) and methamphetamine (OR=0.02, 95%CI: 0.00-0.69). Conclusion: Less new psychoactive substances abuse might be associated with longer duration of MMT treatment. And inappropriate support from family and friends might increase the risk of abusing new psychoactive substances in MMT clients, especially in clients who used opioid.
Adult ; Case-Control Studies ; China/epidemiology* ; Drug Users/statistics & numerical data* ; Humans ; Logistic Models ; Male ; Methadone/therapeutic use* ; Methamphetamine ; Middle Aged ; Opiate Substitution Treatment ; Prevalence ; Psychotropic Drugs/adverse effects* ; Substance Abuse Detection/statistics & numerical data* ; Substance Abuse Treatment Centers ; Substance-Related Disorders/epidemiology* ; Surveys and Questionnaires

Objective: On whole-genome scale, we tried to explore the correlation between obesity-related traits and DNA methylation sites, based on discordant monozygotic twin pairs. Methods: A total of 90 pairs of 6-17 year-old twins were recruited in Chaoyang district, Yanqing district and Fangshan district in Beijing in 2016. Information on twins was gathered through a self-designed questionnaire and results: from physical examination, including height, weight and waist circumference of the subjects under study. DNA methylation detection was chosen on the Illumina Human Methylation EPIC BeadChip. R 3.3.1 language was used to read the DNA methylation signal under quality control on samples and probes. Ebayes function of empirical Bayes paired moderated t-test was used to identify the differential methylated CpG sites (DMCs). VarFit function of empirical Bayes paired moderated Levene test was used to identify the differentially variables CpG sits (DVCs) in obese and normal groups. Results According to the obesity discordance criteria, we collected 23 pairs of twins (age range 7 to 16 years), including 12 male pairs. A total of 817 471 qualified CpG loci were included in the genome-wide correlation analysis. According to the significance level of FDR set as <0.05, no positive sites would meet this standard. When DMC CpG site cg05684382, with the smallest P value (1.26E-06) as on chromosome 12, the DVC CpG site cg26188191 with the smallest P value (6.44E-06) appeared in CMIP gene on chromosome 16. Conclusions: In this study, we analyzed the genome-wide DNA methylation and its correlation with obesity traits. After multiple testing corrections, no positive sites were found to have associated with obesity. However, results from the correlation analysis demonstrated sites cg05684382 (chr: 12) and cg26188191 (chr: 16) might have played a role in the development of obesity. This study provides a methodologic reference for the studies on discordance twins related problems.
Adolescent ; Bayes Theorem ; Beijing ; Body Weight ; Child ; DNA Methylation/genetics* ; Epigenesis, Genetic ; Female ; Genome-Wide Association Study ; Humans ; Male ; Obesity/genetics* ; Twins, Monozygotic ; Waist Circumference